Support Start > Email > Advanced Email Questions > IMAP

IMAP is a method of connecting to a server and reading incoming mail. All modern email programs offer IMAP as well as the older POP3 standard. Our servers fully support either method — it’s up to you, although we recommend IMAP in most cases.

The two methods handle mail differently:

• POP3 downloads copies of each message from the Inbox (only) of the server to your computer, which then keeps its own separate copy of each message. Subsequent changes to that message on your computer don't affect the server or any other program or device reading the same mailbox. POP3 usually also immediately deletes all messages from our servers unless you take extra steps: since your computer has the only copy of the message, you need to rely on your own backups. Even if you set up POP3 so it doesn’t delete all messages from the server, it will mark the server copy as “seen” as soon as it downloads them.
• IMAP always leaves the messages on our servers — in fact, the server copy is the main copy. However, you can have multiple IMAP connections to the server showing you that copy. The server knows when you've read a message, deleted it, replied to it, put it into a folder, and so on. Any other IMAP program or device reading the same mailbox (including our Webmail pages, which use IMAP behind the scenes) will know about all those changes. Most IMAP programs also keep a copy of each message so you can view previously received messages even without Internet access. The messages you've read are backed up using our backup system.

We recommend IMAP if you’re using multiple devices or computers to read your mail, or if you’re using a modern email program such as Mozilla Thunderbird, Apple Mail, or a recent version of Microsoft Outlook that’s optimized for IMAP. (Note that Outlook 2010 and earlier have poor support for IMAP, and we recommend using POP3 instead in older programs like that.)

The instructions we provide for IMAP mailboxes also apply to POP3 mailboxes. When you create a mailbox on our servers, the mailbox can be read using either a POP3 or IMAP connection.

To set up your mail program to use POP3, you’d use the same server name, username, password, etc. The only changes are the connection method (choose POP3 instead of IMAP) and the port number of the incoming mail server (port 110 instead of port 143).

IMAP settings for particular programs

These pages explain how to set up IMAP for some mail programs:

• Outlook Express
• Outlook 2002 and 2003 (not recommended)
• Outlook 2007 (not recommended)
• Outlook 2010 (not recommended)
• Outlook 2011 for Mac
• Outlook 2013
• Outlook 2016 for Windows
• Outlook 2016 for Mac
• Windows Live Mail
• Apple Mail
• Mozilla Thunderbird
• iPad and iPhone

Technical details

Technically advanced users may be interested in the following:

• Our IMAP servers use the standard port 143 for normal IMAP. They also support optional TLS security on port 143 and pure SSL security on port 993.
• The IMAP folder prefix is "INBOX". Many mail programs will automatically detect this, but others may need you to enter this prefix into the account settings if you want to be able to use the same folders on your mail program via IMAP that you see in Webmail.
• The “capabilities” (IMAP extensions) supported by our servers are "IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS MULTIAPPEND UNSELECT IDLE CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS".